Boiler.



H. C. PROX.

BOILER.

APPLICATION FILED 02c. 19. 1914.

1 ,1 89,734. Patented July 4, 1916.

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HERMAN C. PROX, OF TIER/RE HAUTE, INDIANA, ASSIGNOR T0 FRANK PROX COMPANY, OF TERRE HAUTE, INDIANA, A. CORPORATION OF INDIANA.

BOILER.

Specification of Letters Patent.

Patented July 4, 1916.

Application filed December 19, 1914. Serial No. 878,032.

To all whom itma e concern:

Be it known that I, HERMAN C, PRox, a citizen of the United States, residing at Terre Haute, in the county of Vigo and State of Indiana, have invented a new and useful Boiler, of which the following is a specification.

My invention relates to boilers, and its object is to provide a boiler, and especially a down-draft boiler, having a greater capacity for its size, having a more uniform steam-producing action, having an automatic shaking action, having an automatically controlled forced draft controlled in common with a shaking grate, having a sectional construction whereby a broken part can be replaced without disturbing the re mainder, and having Water tubes both below and supporting the grate ,bars for the fuel bed through which the down draft is obtained and at the bottom of the ash pit, so that the hottest parts of the flame may be effectively used, and having both a fuel chamber and fines below and aboveit, all of which are totally surrounded by and separated from each other by water tubes. 7 p

In carrying out my invention in its pre ferred form, I provide a down-draft boiler the bed of fuel in which is supported by a shaker grate which in turn rests on water tubes, sothat the flame descending from the fuel bed strikes such water tubes, and I control this shaker grate automatically by the.

steam pressure. I also providecmeans for producing a forced draft" by forcing airinto the fuel chamber above the fuel bed,.so that the height of chimney required for theboiler may be reduced, and control this forced draft by the steam pressure, preferably operating it by the same mechanism whichopcrates the shaker grate.- I prefer to make the boiler sectional, with the water tubes which support theshaker grate bars forming part of the sections, the main sections comprising outer substantially vertical water tubes or legs cross connected both at the top and bottom and at three intermediate points by water tubes, the watertube at the bottom forming thev bottom of the ash pit, the neXt higher formingthe support for the shaker grate bar, and the highest three forming the walls for the horizontal fines and for separating the fuel chamber from such fines; and I combine with these main sections'certain other sections for directing the draft in the desiredchannels; but in the broader aspects of my invention'it is not essential that the water tubes supporting the grate bars form part of the sections or that they extend parallel to the sections.

Theaccompanying drawings illustrate my lnvention;

Figure 1 is a front elevation of a double boller embodying my invention; Fig. 2 is a vertical sectional view through one of the main or grate bar sections of such boiler; F 1g.,3 is a partial plan view of the boiler shown in Fig. l, to show the position of the controlling mechanism; and Fig. 4 is a side elevation of the boiler shown in Fig. 1, with many of the parts broken away or in section.

The boiler illustrated is made in right and left parts, as clear from Fig. 1, each part in reality constituting a separate boiler and the two parts being mates. Each part of this double boiler comprises a number of vertical transverse sections, of which there are five kinds: a front section 10, having an ash pit door 11 near the bottom, a common firing and draft door 12 near the middle, and one or more flue cleaning doors '13 near the top, the various door openings being separated by transverse water tubes 14 and 15 connecting the verti cal water legs 16, which are also connected by transverse water tubes 17 and 18 at the bottom and the top; a series of main'or grate bar sections 20 havingthese same vertical water legs 16,-which in this case are cross connected by bottom and top water tubes 17 and 1 8 and an intermediate water tube 15 corresponding to those of the front section 10, witha water tube 21 parallel to andbetween the tubes 15 and 18, with vertical H water tubes 22 interconnecting the transverse water tubes 1.5, 21, and 18, and with transverse grate-bar-supporting water tubes 23 on about the same level with and behind the water tube 14: and vertically between the transverse. water tubes 17 and 15; a baflie plate section 25 having the same vertical water legs 16 and transverse water tubes 17,.18,and21 as have the main or grate-bar sections 20 and also having a transverse water tube 26 which is of considerable vertical extent, and reaches from v the level of the water tubes 23 to that of the water tubes 15 of the main sections; a vertical flue section 28 which is like the main or grate bar sections 20 save that the water tubes 15 and 23 are omitted; and a rear section 30 which has the same water legs 16 as have the other sections, the same cross transverse water tubes 18 and 21 as have the sections 20, 25, and 28, and a lower the cross water tubes 15, 17, 18, and 21 of the various sections fit against the corresponding tubesof the neighboring section, the cross water connections 26 and 31 also fitting aga nst the water tubes15 and 17 of the rearmost sections having such water tubes; but the water tubes '23 of the dif-' ferent sections are of less width than the sections .so as to leave spaces between adjacent'ones of such tubes. This provides a fuel chamber 32 between the water tubes 23 and 15 and behind'the firing and draft "door 12, a lower flue 33 below the fuel cha1n-. ber 32 and vertically between the water- 'tubes 17 and 23 of the grate bar sections and the water tubes 17 and 26 of the baffle plate section, a vertical flue 34 in the verticalflueflsection 28 and horizontally be tween the water tubes 26 and 31, and forwardly and rearwardly carrying horizontal flues'35 and 36 between the water tubes 15 and 21 and between the water tubes 21 and 18 respectively. The rear, end of the flue 36. leads into a chimney fitting 37, which conveniently is removable for cleaning purposes and hasa flange 38 for closing the opening between the transverse water connections21 and 31 of the rear section 30.

Each of the various sectionsis provided atone side nearthe bottom with a boss 10 for receiving a nipple 11 for connection to a side bottom header 42, and is provided at the top with a boss 4:3 for receiving a nipple 44 which is connected by an elbow 45 to a. nipple t6 which enters a topnheadcr 17 from the side; This provides a convenient arrangement for disconnecting any section and substituting another for it without disturbing the remainder of the boiler.

The water tubes 23 which form the bottom of the fuel chamber are round externally, and supported on each of them is a shaker grate bar mounted toturn about the axis ofsuch tube. These grate bars 50 conveniently comprise longitudinal members at the two sides of the water tube and cross connectors 51 connectingsuch two longitudinal members and extending over and fitting closely against the surface of the tends forward somewhat beyond the front face of the furnace." There is one of these rods 53 for each half of the double furnace shown in Fig. 1. These operating rods 53 may be reciprocated in any suitable manner for operating the shaker grate bars. In the arrangement shown the forward ends of these operating arms are threaded, and two nuts -5 are mounted on each one, the rod between these two nuts'passingthrough a slot 55 in an arm 56 pivoted on a bracket 57 mounted on the front face of the furnace so that the arm 56 may swing along the rod'53 and by strikingthe nuts 5% operate such rod and the shaker grate bars. The arm" 56 is also slotted to receive an eccentric 58, the two eccentrics 58corresponding to the two rods 53 being mounted on a common shaft 59 carried in bearings 60 on the front face of the furnace. The shaft 85 59 has fixed thereon a ratchet wheel 61,

and has loosely mountedthereon an arm 62 carrying a pawl 63 coiiperating with such ratchet wheel. The arm 62 is connected to one end of a link 64 the other end of which is mountedin a diametrical slot in a disk 65 mounted on a shaft 66 and driven through suitable gearing, such as the worm gearing 67 shown, from the shaft 68 of an electric motor 69. The slot in the disk "65 provides a means for adjusting the rapidity'of operation of the shaft 59, and the nuts 54 provide an adjustment for the throw of the shaker grate bars. 7

lVhile in some instancesthe shaker grate can be operated continuously, I prefer to control its operation automatically in re- I sponse to the steam pressure; For this purpose, I provide in the supply circuit 70' of the motor 69v both a hand switch 71 and an automatic switch 72, which are in series with each other and are conveniently mounted in a box 73'. The automatic switch 72 is preferably a snap switch, which is illustrated diagrammatically, and is connected to a lever 74: pivoted at 75 and operable by any suitable device responsive to steam pressure, such as the regulator 76, connected to the boiler, the lever 74 being provided with a counterweight 77 for adjusting the steam pressure at which the switch 72 is opened or closed. With this control arrangement, the motor 69 is connected in circuit'and operates the shaker gratewhen the steam pressure drops below a predetermined value, and it is disconnected to stop the operation of the shaker grate when the steam pressure rises above apredetermined value. As the operation of the shaker grate tends to increase the combustion and therefore the steam production, the automatic control of the shaker grate in response to the steam pressure will tend to keep the steam pressure constant.

I also provide means for producing a forced draft into the fuel chamber 32.

Conveniently there is a fan 80 operated by the same motor 69 which operates the shaker grate, which fan is connected by a suitable pipe 81 to the two fuel chambers 32 for the two parts of the boiler shown in Fig. 1, the lower end of the pipe 81 being bifurcated just before it leads into the front ends of said two fuel chambers. By this arrangement, the draft is automatically controlled in response to the steam pressure in common with the shaking grate, so as to produce a forced draft and shake the grate whenthe steam pressure is down and to stop both the forced draft and the shaking of the, grate when the steam pressure is up, the forced draft, like the shaking of the grate, tending to increase the combustion and therefore the steam pressure. In addition, the use of the forced draft enables down-draft boilers to be substituted for up-draft boilers without requiring the extra height ofstack which is ordinarily necessary in order to produce the desired draft in clown-draft boilers.

In operation, the fireman fills the fuel chamber 32 with fuel, and thereafter ordinarily is not required to open the fuel door 12, so that the pouring out of smoke into the furnace room which usually occurs when such door is opened for stoking is prevented. The flames from the under part of the bed or fuel strike the water tubes 23 and 17 and heat the water therein and then pass by way of the fines 33, 34, 35, and 36 into the smoke stack, heating the various water tubes as they pass and providing for great efliciency in transferring the heat from the hot gases to the water. The presence of water in the water tubes 23 not only serves to heat the water in the most effective parts of the flames, but also tends to keep the grate bars cool so that they will not be destroyed or warped by the action of the flames. The

arms 52 project up into the bed of fuel so that they are not materially acted on by the flames. The steam pressure is maintained automatically by the action of the. automatic switch 72 and the parts controlled thereby, and the stoking is uniform throughout the entire fire, so that there is a uniform distribution of the air through the fire and consequently better combustion. However, the rocking grate bars may also be manipulated manually when desired, by suitably reciprocating the rods 53; this may be done most conveniently by throwing out the pawl 63 and placing an extension on the arm 56 for operating it.

While the water tubes 23 are shown as forming'integral parts of the sections 20, it is not essential thatthey be integral, or even that they be in the planes of such sections, as my invention is intended to include the use of water tubes supporting shaker grate bars in a down-draft furnace however such water tubes and grate bars extend in the furnace.

I. claim as my invention:

A sectional down-draft boiler comprising a plurality of sections having water legs and cross water tubes connecting the water legs, some of such sections having one of such cross water tubes below the ash pit and another between the ash pit and the fuel chamber of the boiler, and grate bars mounted on said last-named cross water bars to rock thereon. V

In witness whereof I have hereunto set my hand at Indianapolis, Indiana, this seventeenth day of December, A. D. one thousand nine hundred and fourteen.

HERMAN C. PROX.

Witnesses:

J OSEPHINE GAsPnR, G. B. SGHLEY.

Copies 0! this potent may be obtained for five cents each, by addressing the "Commissioner of latent, Washington, D. c." 

